1. Field of the Invention
The present invention relates to an organic light emitting display device and a method of manufacturing the same, and more particularly, to an organic light emitting display device, which may be manufactured with a relatively small number of masking operations and may resolve coarse doping in a capacitor, and a method of manufacturing the same.
2. Description of the Related Art
An organic light emitting display device is fabricated on a substrate, in which a thin-film transistor (TFT), a capacitor, and a wiring for connecting them to each other are formed.
Generally, to form a fine structure pattern having a TFT, such a fine pattern is transferred to a substrate for fabricating an organic light emitting display device by using a mask including the fine pattern.
Generally, a photolithography operation is performed to transfer a pattern by using a mask. In a photolithography operation, photoresist is uniformly applied onto a substrate, the photoresist is exposed to light by using an exposer, e.g., a stepper, and in case of positive photoresist, the exposed photoresist is developed. Furthermore, after the photoresist is developed, a pattern is etched by using residue photoresist as a mask, and unnecessary photoresist is removed.
In such an operation for transferring a pattern by using a mask, a mask having a necessary pattern shall be prepared. Therefore, as a number of operations using masks increases, the overall fabrication costs increases due to the cost for preparation of the masks. Therefore, it is necessary to reduce a number of times of using masks as much as possible.
Meanwhile, to reduce a number of times of using masks, it may be considered to form one of electrodes of a capacitor together with an active layer using a poly silicon crystal and implanting an impurity thereto later. In this case, if a plurality of regions is formed at once as a single layer to reduce a number of times of using masks, a capacitor electrode may be covered by a thin-film layer formed prior to impurity implantation, and thus the capacitor electrode may not be uniformly doped. If a capacitor electrode is not uniformly doped, electric resistance increases, and thus a desired capacitance may not be secured. Therefore, it is necessary to reduce a number of times of using masks and avoid increase of resistance due to coarse impurity implantation.